basement walls Renovation question

Hello!

I'm currently finishing my basement. I install 2 inch xps on the walls and 1 inch on the floor. I'm installing plywood on the floor today and then studding out the walls after that. The walls are going to be built on top of the plywood because they aren't going to be load bearing in any way... Just a ring of walls against the xps to hold electricity and sheet rock.

Anyway, because the walls are going to be built on the subfloor is there any reason to use a treated board on the bottom? I don't think there is but figured it'd be worth asking.

Local code here requires that any wood in contact with concete be treated wood or have a barrier between the two. Moisture will wick through concrete. I have stripped out 30lb felt and stapled it to the contact side of KD lumber, but the sleepers were installed to allow air to move from the floor bays into a continuous space behind the outside stud wall and then open to the joist bays above so that it could breathe. It was also an older home with no history of any moisture problems in the basement. Suggest you check your local code and remember, building codes are a minimal standard.